Mobile wireless devices access communication networks via wireless access nodes, such as via base stations in cellular wireless communication networks, via wireless access points in Wireless Fidelity (WiFi) networks, or the like. There are various services and applications which may make use of the geographic location of a mobile wireless device, and there are several types of location determination processes by which the location of a mobile wireless device may be determined for use in supporting such services and applications. Most, if not all, such location determination processes rely on accurate calibration of the bias or offset that is introduced by the wireless access node via which the mobile wireless device communicates. For example, while a time-of-arrival (ToA) measurement from a base station to a cellular device (e.g., a cellular phone, a smartphone, or the like) may be used to estimate the location of the cellular device, this ToA measurement includes an offset introduced by the base station due to internal delays of the base station. While existing mechanisms for calibration of a wireless access node attempt to measure these delays for various modules of the wireless access node (e.g., each radio frequency (RF) module of a base station), and reduce them to acceptable levels, this is a complex process and accuracy is not guaranteed. In addition, environmental factors associated with a wireless access node can introduce additional offset that is unique to the wireless access node and that is not accounted for by existing mechanisms for calibration of a wireless access node.